I used the heck out of this Metro station while in Paris last week. We stayed in La Defense and it's a LONG way from everything you want to see in Paris by foot or taxi (expensive).
So I quickly learned that metro is the way to go - this station was like a 5 minute walk outside the hotel and I was easily able to purchase one-way tickets for anywhere I wanted to go.
I found staff helpful when asked questions (only once) or if we needed to purchase from them (again once) and they have clean and on-time trains. Two or three exits make it easier to come out where you need to be. read more